Silicone oils are ingredients that are particularly sought after in cosmetics because they impart excellent lubricating and waterproofing properties.
Moreover, by comparison with classical oils, silicone oils form a protective film over the skin, protecting it from dehydration with no greasy effect being observed.
Until now, studies performed have not allowed appreciable proportions of silicone oils to be incorporated satisfactorily into emulsions of the oil-in-water type. Incorporation of silicone oils is limited to approximately 15% maximum and the silicone oils employed are cyclic volatile silicone oils and polydimethylsiloxanes (linear silicones) with a low viscosity (&lt;100 centistokes).
Other studies have been performed with a view to obtaining emulsions of the oil-in-water type based on silicone oils using various surfactants, particularly nonionic and ionic surfactants. Such silicone oil-based, oil-in-water emulsions are described in U.S. Pat. No. 4,917,891, French Patent No. 2,485,923, European Patent EP 76,146, and U.S. Pat. 4,788,001.
It has been shown by these patents, however, that the use of classical surfactants does not always produce good emulsification of the silicone oils in the water.